SPECIFICATIONS 


Electric  Railway 
Bridges. 


1902 


By  C.  S.  Davis 


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learning  anb  |Tabor. 

LIBRARY 


University  of  Illinois 


CLASS. 


BOOK. 


VOLUME. 


H Z.<5 


Accession  No. 


TABLE  OF  CONTENTS.  ‘ 

GENERAL  DESCRIPTION.  Paragraphs. 

CLASSES  i 

L.  20 2-  3 

L.  30 4-  5 

L.  40 6-  7 

Recommendation  

TYPE 9 

MATERIAL  10 

CLEARANCE  

Single  Track if 

Double  Track . 12 

Curves 13 

CURVATURE  14 

END  BEAMS 15 

STRINGER  SPACING 16 

GIRDER  SPACING 17 

FLOOR  DECK 18 

Rails  iq 

Cross-Ties  20 

Guard-Rails  21 

PLANS  22 

Stress  Sheet 23 

Working  Drawings 24 

Changes  25 

Extras 26 


5 t 


II 


PATENTS  

PROPOSAL  

Price  

Time  

Delays  

Damage 

LOADS 

DEAD  LOAD  

LIVE  LOAD 

L.  20 

L.  30 

L.  40 

WIND  LOADS 

Fixed  Load  

Moving  Load  

Additional  Section 

Initial  Stress 

Lateral  Struts  

CENTRIFUGAL  FORCE 

Additional  Section 

Speed 

LONGITUDINAL  STRESSES 

UNIT  STRESSES, 

TENSION 

COMPRESSION 

SHEARING  

BEARING 

BENDING 

ALTERNATE  STRESSES  . . . 

COMBINED  STRESSES 

TURNTABLE  DETAILS 

VALUES  OF  © AND  ~ 


27 

2S 

29 

3;J 

31 

3J 

33 

34-  35 
33 
37 
3^ 

39 

40 

41 
4'2 

43-  44 

45 

46 

47 
4S 

49 

50 

51 
51 
51 

51 

5i 

51 

5* 

5f 


Ill 


VALUES  OF  <P  AND  ^ 53 

SHEARING  AND  BEARING  VALUE  OF 
RIVETS 54 

DETAILS  OF  DESIGN. 

LIMITING  SIZES. 

Thickness  - • • 55 

Angles 5^ 

Bars 57 

Columns 5&~  59 

Flanges  60 

Pins 61 

END  BEARINGS. 

Lead  62 

Anchors  63 

Pin  Bearings  64 

Sliding  Ends  65 

Roller  Ends  66-  69 

Pier  Plate  : 70 

CAMBER. 

Trusses  71 

Plate  Girders  72 

Framing  Out 73 

RIVETS 74 

NET  SECTION  75 

ROLLED  BEAMS  76 

BUILT  BEAMS  77 

Flanges  78-  79 

Web  Plate  80 

Effective  Depth  Si 

Flange  Splice 82 

Web  Splice 83 

Stiffeners  84-  87 


IV 


Fillers  

Rivet  Spacing 

Bracing  

End  Finish  

Ends  Faced  

PIN-CONNECTED  BRIDGES. 

Compression  Members  

Battens  

Lattice 

Riveting  

Pin  Plates 

Pin  Holes 

Splices 

Eyebars 

S iffened  Sections 

Adjustable  Members  

Stringers 

Beams  

Bracing 

Top  Struts 

Knees  

Cross  Bracing 

Portals  

VIADUCTS  OR  TRESTLES. 

Type  

Bents  . 

Towers  

Rocker  

Batter  

Bearings  

Anchorage  

Bracing 


88-  89 
90-  91 
92~  93 
94-  95 
06 


97-  98 
99 

100 

101 
T 02- 1 03 

10* 

105 

106 

107 
TOS 

109 

110 

in 

112 

113 

114 

115 

1 16 
n;’ 
ITS 

1 19 

120 
12  r 

22-12^ 
12  I 


V 


SWING  BRIDGES. 

Floor  System I25 

Trusses  I26 

Turntable  1 27 

Disc  Center  ...  128 

Roller  Center 129 

Rim  Bearing .130-132 

Latches  135 

End  Lifts  134 

Rail  Lifts  135 

End  Signa’s 136 

Machinery  137 

Cables  138 

Motors 1 39- 1 40 

Material  141 

Tender’s  House  . . 142 

SHOP  WORK. 

FIRST  CLASS  143 

STRAIGHTENING  144-145 

PUNCHING 146 

REAMING  147 

DRILLING 148 

RIVETING 149 

FACING  150-151 

FITTING 152 

PLANING  153-155 

PIN  HOLES  156-158 

LATHE  WORK 159 

EYEBARS. 

Material  160 

Heads  161 

, Annealing , 162 


VI 

ADJUSTABLE  RODS. 

Loop  Eyes 163 

Upsetting  164 

Annealing 165 

PAINTING. 

Cleaning  166 

Before  Assembling 167 

Inaccessible  Parts  16S 

Machined  Surfaces 169 

Other  Parts  170 

Application  171-174 

FIELD  WORK. 

READY  FOR  RAILS  175 

FLOOR  DECK  176 

FALSEWORK  177 

INTERRUPTING  TRAFFIC  17S 

RENEWAL  179 

ANCHORAGE 180 

WATCHMEN  181 

LAWS  182 

RISKS  183 

REAMING  184 

RIVETING 185 

TURNED  BOLTS 186 

PILOT  NUTS  187 

PAINTING. 

Cleaning  iSS 

Rivet  Heads x8e) 

First  Coat  . 193 

Second  Coat  TgL 

Application jq.3 


VII 

QUALITY  OF  MATERIAL 

WROUGHT  STEEL. 

Process  193 

Finish  194 

Variation  195 

Phosphorus  196 

Test  Pieces  197-200 

Ultimate  Strength 201 

Elastic  Limit  202 

Elongation  203 

Reduction  of  Area  204 

Fracture  205 

Bending 206 

Hard  Steel  207 

Medium  Steel  20S 

Soft  and  Rivet  Steel 209 

Drifting  210 

Duplicate  Tests  21 1 

Marking  212 

Eyebar  Tests  213-218 

WROUGHT  IRON. 

Grade  219 

Test  Pieces 220 

Ultimate  Strength  221-222 

Elastic  Limit  22^ 

Elongation  224 

Bending  ....225-226 

CAST  STEEL. 

Process  227 

Phosphorus 228 

Coupon  229 

Annealing 2?o 


VIII 


Blow  Holes  23J 

Ultimate  Strength  232 

Elastic  Limit 233 

Elongation  234. 

Reduction  of  Area 235 

CAST  IRON. 

Grade  230 

Coupon  237 

Tests  . 238 

PHOSPHOR  BRONZE. 

Composition  239 

Coupon  * 240 

Tests  241 

BABBITT  METAL 242 

TIMBER  243 

PAINT. 

Oil  244 

Red  Lead  245 

First  Field  Coat 246 

Second  Field  Coat 247 

INSPECTION. 

INSPECTOR  24S 

NOTICE  OF  ROLLING 249 

SURFACE  INSPECTION 250 

SUBSEQUENT  DISCOVERY  OF  DE- 
FECTS   25  r 

MARKS  252 

FACILITIES  253 

FULL  SIZED  TESTS  254 

MAINTENANCE 255 

FIRST— PAINTING  256 

SECOND— INSPECTION  2^7 


SPECIFICATIONS 

FOR 

Electric  Railway  Bridges. 

By  C.  S.  DAVIS. 

1902. 


GENERAL  DESCRIPTION. 

(i)  Electric  railway  bridges  shall  be  classified  in  ac- 

CTasses . eordance  with  their  capacity  or  loading  they  will  be  called 

upon  to  carry.  In  these  specifications  there  will  be  three 
general  classes — L 20,  L 30  and  L 40.  Intermediate  or 
heavier  classes  may  be  used  if  so  desired. 

L-  20-  (2)  Bridges  of  this  class  shall  be  designed  to 

carry  a train  of  electric  railway  passenger  cars,  and  also 
a light  freight  or  express  service.  The  weight  of  the 
loaded  cars  should  not  exceed  80,000  pounds,  each,  and 
the  length  of  each  car  should  not  be  less  than  40  feet. 

(3)  Note; — An  84-ton  locomotive  (engine  and 
tender)  may  be  used  during  construction  to  haul  sup- 
ply trains  at  slow  speeds,  or  a 56-ton  locomotive  may  be 
used  in  regular  service. 

L 3Q  (4)  Bridges  of  this  class  shall  be  designed  to 

carry  a train  of  80,000  pounds  capacity  freight  cars 
hauled  by  an  electric  motor.  It  is  not  intended  to  in- 


— 2 — 


ciude  pressed  steel  cars  or  cars  less  than  40  feet  in 
length  in  this  class. 

(5)  Note — A 127-ton  locomotive  (engine  and 
tender)  may  be  used  during  construction  to  haul  sup- 
ply trains  at  slow  speeds,  or  an  85-ton  locomotive  may 
be  used  in  regular  service. 

^ 40  (6)  Bridges  of  this  class  shall  be  designed  to 

carry  a train  of  100,000  pounds  capacity  freight  cars 
hauled  by  an  electric  motor.  It  is  intended  to  include 
pressed  steel  cars  and  other  cars  with  a short  wheel 
base  in  this  class. 

(7)  Note — A 170-ton  locomotive  (enigne  and 
tender)  may  be  used  during  construction  to  haul  sup- 
ply trains  at  slow  speeds,  or  a 113-ton  locomotive  may 
be  used  in  regular  service. 

Recommendations. 

(8)  Although  loading  L 20  is  sufficient  for  the 
traffic  of  electric  railway  lines  at  the  present  time,  the 
Author,  in  view  of  the  rapid  development  of  the  service, 
recommends  a loading  of  not  iess  than  L 30.  See  tables 
of  equivalent  loads  in  the  appendix. 

Type (9)  The  type  of  bridge  used  will  depend  upon  local 

conditions,  but  the  following  will  be  preferred: 

Spans  of  20  feet  or  less — Rolled  beams. 

Spans  20  to  100  feet — Plate  girders. 

Spans  100  to  120  feet — Riveted  trusses. 

Spans  over  120  feet — Pin-connected  trusses. 

Material  (IO)  All  timber  for  ties  and  guard-rails  shall  be  white 

oak.  All  metal  shall  generally  be  medium  steel,  but  soft  steel, 
wrought  iron,  cast  steel  and  cast  iron  may  be  used  as  noted 
hereafter. 


3— 


Clearance 


Single  Track 


Double  Track 


Curves 


( 1 1 ) All  single 
track  through  bridges 
on  straight  track  shall 
have  a clear  opening 
of  not  less  than  that 
shown  by  the  accom- 
panying diagram. 


(12)  For  double  track  bridges,  the  clear  width 
shall  be  increased  by  an  amount  equal  to  the  distance 
between  centers  of  tracks. 

(13)  When  a bridge  is  on  a curve  additional 
c earance  must  be  provided  so  that  the  net  clearance 
shall  not  be  less  than  given  above.  Curvature  of  track 
and  tip  of  car  due  to  super-elevation  of  outer  rail  must 
both  be  considered. 


(14)  When  a bridge  is  located  on  a curve  the  center 

Curvature 

line  of  the  bridge  must  be  parallel  to  the  chord  of  the  curve 
connecting  the  centers  of  the  track  at  the  ends  of  the  span, 
and  must  bisect  the  middle  ordinate  of  the  curve.  In  double 
track  bridges  the  center  between  tracks  shall  be  used  instead 
of  center  line  of  track  as  above. 

End  Beams 

(15)  All  through  bridges  shall  have  end  beams  to 
carry  the  ends  of  stringers  over  piers  and  abutments. 

Stringer  spacing 


(16)  When  two  lines  of  stringers  are  used  for  each 


Girder  Spacing 


Floor-deck 


Rails 


Cross-ties 


Guard  rails 


— 4— 

track  they  shall  be  spaced  6 feet  6 inches  apart  center  to 
center.  When  four  lines  of  stringers  are  used  for  each 
track  the  distance  from  the  center  of  the  track  to  point  mid- 
way between  each  pair  of  stringers  shall  be  2 feet  6 inches, 
and  they  shall  be  so  spaced  that  the  bolt  fastening  the  guard- 
rail to  the  stringer  shall  pass  just  outside  the  flange  of  the 
outer  stringers. 

(17)  Deck  girders,  less  than  80  feet  in  length  shall  be 
spaced  6 feet  6 inches  apart  center  to  center. 

Deck  girders  80  feet  or  more  in  length  shall  be  spaced 
8 feet  apart  center  to  center. 

(18)  The  floor-deck,  consisting  of  rails,  guard-rails, 
cross-ties  and  the  fastenings  for  the  same,  shall  be  con- 
structed as  follows : 

(19)  The  rails  shall  be  what  are  known  as  T 
rails  and  shall  weigh  not  less  than  70  pounds  per  yard ; 
they  shall  be  spiked  to  each  cross-tie  with  two  spikes  to 
each  rail. 

(20)  The  cross-ties,  of  white  oak,  shall  be  spaced 
at  intervals  of  not  more  than  16  inches  center  to  center, 
and  they  shall  not  be  less  than  7 inches  by  8 inches  by 
9 feet  for  stringers,  or  girders  spaced  6 feet  6 inches 
apart  and  8 inches  by  9 inches  by  11  feet  for  girders 
spaced  8 feet  apart.  They  shall  be  dapped  at  least  1-2 
of  an  inch  over  the  stringers,  but  must  not  be  dapped  to 
a thickness  less  than  61-2  inches. 

(21)  A guard-rail,  of  white  oak,  shall  be  used 
along  the  outside  of  each  rail,  and  it  shall  be  notched 
1 inch  over  the  cross-ties  and  bolted  to  the  stringers 
through  every  third  tie  with  a 3-4  inch  round  bolt.  A 
cast  iron  washer  or  clip  shall  be  used  under  each  head, 


Flans. 


Stress-sheets 


Working 

drawings 


Changes 


— 5— 

and  a cast  iron  washer  and  nut  lock  under  each  nut.  The 
distance  between  inner  faces  of  the  guard  rails  shall  be 
7 feet. 

(22)  The  Contractor  shall  prepare  stress-sheets  and 
working  drawings  upon  tracing  linen  which,  upon  comple- 
tion of  the  work  are  to  become  the  property  of  the  Railway 
Company. 

(23)  Before  beginning  work,  the  Contractor  shall 
submit  for  formal  approval  stress  sheets  of  a uniform 
size,  18  by  24  inches,  showing: 

(a)  Length  of  span  center  to  center  of  end  bear- 
ings. 

(b)  Height  of  truss  between  centers  of  chords  or 
distance  back  to  back  of  flange  angles  for  stringers, 
beams  and  girders. 

(c)  Live  and  dead  loads  assumed  in  making  cal- 
culations. 

(d)  Stresses  in  all  members. 

(e)  Sections  and  cross-sectional  areas  of  all  mem- 
bers. 

(f)  Size  of  rivets  in  principal  members  and  re- 
quired rivet  spacing  in  the  flanges  of  all  stringers,  floor 
beams  and  girders. 

(24)  Before  beginning  actual  construction  at  the 
bridge  shops  the  Contractor  shall  submit  for  formal 
approval  a complete  set  of  working  drawings  of  a uni- 
form size,  24  by  36  inches. 

(25)  After  the  approval  of  the  plans,  no  changes 
shall  be  made  without  the  written  consent  of  the  Rail- 
way Company. 

(26)  No  extra  charges,  due  to  changes  made,  shall 


Extras 


— 6— 


Patents 

Proposal 

Price 

Time 

belays 

Damage 

LOADS 

Dead  Load 


be  allowed  except  as  agreed  upon  in  writing  at  the  time 
the  changes  are  accepted. 

(27)  If  any  patented  devices  or  parts  are  used,  the 
Contractor  shall  protect  the  Railway  Company  against  all 
claims  on  account  of  such  patents. 

(28)  All  proposals  must  be  accompanied  by  stress- 
sheets  and  an  estimate  of:  the  weight  of  each  span. 

(29)  The  price  named  in  the  proposal  shall  be  ill 
Cents  per  pound  of  the  finished  weight  of  the  metal,  and 
shall  be  for  the  bridge  erected,  ready  for  the  rails.  The 
timber  guard-rails  and  cross-ties  will  be  furnished  de- 
livered at  the  bridge  site  by  the  Railway  Company  but 
shall  be  framed  and  put  in  place  by  the  Contractor. 

(30)  Each  Bidder  shall  state  in  his  proposal  a time 
in  which  he  can  complete  the  bridge  after  the  acceptance 
of  his  proposal,  and  the  Contractor  shall  agree  to  com  • 
plete  the  bridge  in  the  time  mentioned  in  his  proposal. 

(31)  When  delays  occur,  due  to  causes  beyond  the 
control  of  the  Contractor,  an  extension  of  time  will  be 
granted.  However,  notice  of  such  delay  must  be  given 
by  the  Contractor  at  the  time  of  its  occurrence. 

(32)  If  any  damage  is  caused  by  the  failure  of  the 
Contractor  to  complete  the  bridge  in  the  time  agreed 
upon  he  shall  be  liable  for  all  such  damage. 

(33)  All  bridges  shall  be  proportioned  to  carry  the  fol- 
lowing loads : 

(34)  A dead  load  consisting  of  the  entire  weight  of  the 
structure.  The  weight  of  the  rails,  cross-ties,  guard-rails  and 
the  fastenings  for  the  same  shall  not  be  assumed  at  less  than 
300  pounds  per  foot  of  track. 

(35)  The  weight  of  the  floor  system  shall  be  considered 


— 7 — 


Live  Load 


L 20 


L 30 


L 40 


Wind  Loads 


Fixed  Load 


Moving  Load 


Additional 

Section 


as  applied  at  the  loaded  chord  and  the  remainder  of  the  dead 
load  as  applied  equally  between  the  loaded  and  unloaded 
chords  of  the  main  trusses. 

(36)  The  live  load  used  in  the  calculations  shall  be  one 
of  the  following  'loadings  : 

(37)  A continuous,  uniformly  distributed  moving 
load  of  2000  pounds  per  foot  of  track,  and  a concen- 
trated load  of  20,000  pounds  so  placed  as  to  produce 
the  maximum  effect  in  every  case. 

(38)  A continuous,  uniformly  distributed  moving 
load  of  3,000  pounds  per  foot  of  track,  and  a concen- 
trated load  of  30,000  pounds  so  placed  as  to  produce 
the  maximum  effect  in  every  case. 

(39)  A continuous,  uniformly  distributed  moving 
load  of  4,000  pounds  per  foot  of  track  and  a concen- 
trated load  of  40,000  pounds  so  placed  as  to  produce 
the  maximum  effect  in  every  case. 

(40)  All  bridges  shall  be  braced  to  resist  the  follow- 
ling  wind  loads : 

(41)  The  lateral  system  for  the  unloaded  chords 
of  a bridge  shall  be  designed  for  a fixed  wind  load  of 
150  pounds,  and  the  lateral  system  for  the  loaded  chords 
shall  be  designed  for  a fixed  wind  load  of  200  pounds 
per  foot  of  bridge. 

(42)  The  lateral  system  for  the  loaded  chords  of  a 
bridge  shall  be  designed  for  a moving  wind  load  of 
300  pounds  per  foot  of  bridge  in  addition  to  the  fixed 
wind  load. 

(43)  When  the  stresses  from  wind  loads  in  the 
floor  beams  and  chords  of  the  main  trusses  exceed  one- 
third  of  the  stresses  from  live  and  dead  loads,  addition- 
al section  must  be  provided  for  such  excess 


— 8— 


Initial  Stress 


Lateral  Struts 


Centrifugal 

Force 


Additional 

Section 


Speed 


Longitudinal 

Stresses 


(44)  When  the  top  flange  of  a floor  beam  acts  as 
a strut  for  the  lateral  system,  additional  section  must 

be  provided  for  such  excess. 

(45)  All  adjustable  lateral  rods  shall  be  propor- 
tioned for  an  initial  stress  of  10,000  pounds  in  addition 
to  the  stresses  as  determined  above. 

(46)  Lateral  struts,  in  addition  to  the  wind  load 
stresses,  shall  be  considered  as  taking  the  resultant 
from  an  initial  stress  of  10,000  pounds  on  each  of  the 
adjustable  rods  attached  to  them. 

(47)  When  a bridge  is  on  a curve,  the  lateral  bracing 
shall  be  designed  to  resist  the  stresses  due  to  centrifugal 
force  in  addition  to  the  stresses  due  to  wind. 

(48)  To  resist  the  stresses  from  centrifugal  force, 
additional  section  must  be  provided  in  the  floor  beams 
and  in  the  chords  of  the  main  trusses  to  resist  the  chord 
stresses  of  the  lateral  truss  due  to'  the  centrifugal  force. 

(49)  Speed  for  the  moving  load  shall  be  assumed 
at  4<>2d  miles  per  hour  where  d is  the  degree  of  curva- 
ture. 

(50)  Due  allowance  shall  be  made  for  the  stresses  due 
to  stopping  the  load  upon  the  bridge.  The  coefficient  of 
friction  between  the  wheels  and  the  rails  shall  be  assumed 
at  0.20. 


Unit  stresses 


9— 


(51)  Ail  members  shall  be  so  proportioned  that  the 
stresses  in  pounds  per  square  inch  will  not  exceed  those 
given  by  the  following  formula; 


/ 


— IO — 


Wrought  Iron. 


Soft  Steel. 


TENSION 

Main  members 

Counters  and 
long:  hangers 

Rolled  beam 

flanges 

Built  beam 

flanges 

Beam  Hangers 
Bracing 
COMPRESSION 
Chords 

Posts 

Lateral  struts 

SHEARING 
Web  plates 
Shop  rivets 
Field  rivets 
Pins 

BEARING 
Shop  rivets 
Field  rivets 
Pins 
Rollers 
Masonry 

BENDING 
Pins 


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ALTERNATE  — n— 

STRESSES  use  S.T-r^rJ  ill  place  of  j s-  2 ! in  the  above  formulae 

Tension  and  + ^ /2-ej 

compression  and  proportion  for  both  compression  and  tension  and  use 


the  larger  area  obtained. 

COMBINED 

STRESSES 


Compression 
and  bending 

Tension  and 

A = 

! c + 

My  | • t 

bending 

A - 

I T4. 

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r2  i ‘ 1 

' TURNTABLE 
DETAILS 

Bearing:  Cast  iro11  wheels  on  a cast  iron  track 


Bearing:  Cast  stee^  wheels  on  a cast  steel  track 


Bearing: 


Hard  steel  rollers  on  a hard  steel  track 


Bearing: 


Phosphor-bronze  discs  on  steel 


400  D | 

4°°  D|*-e> 

2500  D|.ri§| 


NOTE 

© 

<t>  =* 

y = 

r — 
1 - 
f = 
A = 
C =» 
T- 
M - 
D - 


Dead  load  stress  4-  Total  stress. 

Maximum  Stress  of  the  lesses  kind  — Maximum  stress  of 
the  greater  kind. 

Distance  from  centre  of  inertia  to  outer  edge  of  the  section 
in  inches. 

Radius  of  gyration  in  inches. 

Length  of  member  in  inches. 

Unit  stress  from  above  formulae 

Required  cross  sectional  area.  • 

Total  direct  compression  in  pounds. 

Total  direct  tension  in  pounds. 

Bending  moment  in  inch  pounds. 

Diameter  in  inches. 


The  same  required  areas  will  be  obtained  by  dividing 
the  live  load  stress  by  the  first,  factor  of  the  above  formulae 
and  the  dead  load  stress  by  two  times  the  same  factor  and 
adding  the  two  quotients  as  by  the  use  of  the  above  formulae. 


12  — 


(52)  Values  of  ® and 


© 

2 

1 2-e 

© 

2 

| '2-0 

© 1 2 

j 2-0 

© 

2 

2-e 

j.000 

1.005 

.010 

015 

.020 

i .0000 
1 .0025 

1 .0050 
1 .0076 

I.OIOI 

.200| 

■205J 

.210) 

•2151 

.220 

I.IIII  .4OO  I.25OO 
I.II42  .405  I.2539 
‘1-1173  410  j 1.2579 
1-12051.415!  1.2618 
I. I236|.42o|  I.2658 

600 1 1 .4286 1 .800 ! 1 .6667 1 
•605i1.4337i.805j1.6736! 
.610!  1.4388]  .810T1. 68071 
.6 1 5 1 1 .4440  i .8 1 5T 1 .6878 1 
.620 1 1 .4493 1 .820 1 1 .6949 ; 

.025 1 1 .0127  j .225]  1 . 1267 1 .425  j 1 .26981 .6251 1 .4545 
•030 1 1 .01 52 1 .230;  1 .12991 .4301 1 .27391 .6301 1 .4598 
•035 1 1.01781.235!  1.1332!  .435' 1 .2780T.635 1 1 .4652 
.0401 1.0204I.2401 1.1364I.4401 1.2820I.6401 1.4706 


.82511.7021; 

.830IT.70941 
-835j  i-7I67i 
.840!  1.7241; 


•‘>15  1 -0230!  -245!  1 • 1 3961-445 1 1 -2862  j .645 1 1 .4760!  .84  5 ! 1 .73 16; 


1.0501 1 .02561. 2 50!  1.1429I.4501 1.29031.650!  1.481 5I.8501 1. 739 1 1 
i -055 1 1 -0283 1 .255  j 1 . 1461 ; .455J1 .2945L655 1 1 .4870*8551 1 .7467  i 
,o6o|  1 .03091 .260]  1 . 14941 .4601 1 .29871 .66o|  1 .4925!  .8661 1 -7544 
i -065  [ 1 .0336!  .265 1 1 . 1 527 1 .465J1 .30291 .665 1 1 .4981 1 .865 ! 1 .7621 ; 
.070!  1.03631.270!  1.1561  L470J1.  3072 1 .670  j 1. 5038T.8701 1.76991 


075 1 1 .0390J.275 1 1 . 1 594 1 -475!  I-3II5!  -675 1 1 -50941  -875 ! 1 -7778; 
080  j 1.04171.2801 1 .16281 .480]  1 .3 1 58T.680!  1 .5 1 5 1 ! .S80T 1 .7857: 
l-085i1.0444j.285J1.1662l.485l1.3201  j .685J1.5209J.8S5j  1 .7937! 
1.090- 1. 0471 1.290  i_1.1696j.490f  1. 32451.6901 1.5267I.890I1.8018; 
:-095i  i-O499j-295rr-i730l-495i  1-3289! .695 j x .5326!  895T1 .8100! 
.100I1.0526J.3001 1.1765I.5001 1.3333I.700I1.5385J.900I  t.8i82| 
1 . 105 1 1 .0554J.305 1 1 . 1 799T.505  j 1 .3378!  .705  j 1 .5444J.905  j 1.8265! 
.110l1.0582L310J1.1834l.510l1.3423l.710j  1. 5504I.910T1. 83491 
1 1 5 i- 0610! . 3151 1.18691.515!  1.34681.71511.55641.915!  1.8433 

. 1 20 1 1.0638|.320i  1. 1905  | -520|  I.35 14|.720|  1. 5625  |.92o!  T.  85  IQ: 


I2S  I I.o667|.32S!  I . I Q40 1 . ^2  ^ 

i30il.0G95l.330l  I. I976I.53O 


1 4P  1.0753]  .3401 1 .2048I.540 


1 -3559! -725lI-5686l. 925!  1. 86051 
1 -3605 ! .730!  1 . 5748 1 .930  [ 1.8692] 


135j1.0724J.335iL-2012l.535  1.36521.73511.5810!. 935!  1.8779 


1 -3699 1 -74o!  1 . 5873 1 -94°T  i .8868 ; 


1 45 : 1 .0782 1 .345 1 1 -2085  j . 545  Ji  .3746 1 .745 1 1 .5936]  .94  5 Jr  .8957 ! 


.1501 1. 081 1 1 -35o|  1.2121 1 .5501 1.3793!  .750I1.6000I.9501 1.9048! 
L1551 1. 08401.355!  r .2 1 58X-S55T 1 -3841 1 - 755  Ii-6064j.955l1.9139! 
. 160  1.0870I.360J1.2195J.5601 1.3889!. 760I i.6i29j.96oTi  9231] 
1 . 165 1 1 .0899  j .365J 1 .2232  j .565  j 1 .3937  j .765  j 1 .61 94J.965T  1 .9324  j 
L170I1.0929J.370J1.2270J.570!  i-.3986I.770l  1. 6260]  .970]  1.9417! 

' • 1 75 1 1 -°959  i -37.5ji  .2308 1 -575 1 1 -4035 1 -775 ! 1 -6327 1 .975 1 1 -95 1 2 ! 
L.180!  i. 09891.3801  T.2346I.580I1.4085J  7801 1. 6393 1.9801 1. 9608; 
. 185 1 1 . 1019  L385J1 .2384J.585T  1 .41 34I".  785 1 t .6461 1 .985T1 .9704: 
• T90!  i.  io5o|.39o[i.  2422  j . 590  f 1. 41841.790!  1. 6529!. 990T1. 9802! 
1 . 195 1 1 . io8oj  .395  J 1.2461  j .595!  1 .4235 1 .795 1 1 .6597  j .995 ! 1 .9901 
!•'•••! !•■••] | — l j.  ...| ji.ooj2.oooo: 


— !3— 

(53)  Values  of  <J>  and 


4> 


2_ 

2 + cj> 


2 

2 +-  $ 


015 

020 


<E> 


_2 

2 +-  cf> 


-4-.  <$> 


2 

2 +■  $ 


<t> 


2 

2 -t-  <t> 


000  j 1. 0000  .200  j 0.909 1 400  j 0.8333!. 600 
005  0.9975I.205I0.9070  .405 1 0.83 1 6 1.605 
oro  0.9950! .210I0.09501 .41010.8299! .610 
0.9926 1 .2 1 5 j 0.9030  j .4 1 5 1 0.8282 1 .6 1 5 


o.  76931.800!  0.7 1 43 
o.7678!.8o5|o.7i3t 
o.  76631.81010. 7118 
0.7648!. 81510.7105 


0.9901 1 .220 1 0.9009!  .420^0.8265 1 .620(0.76341 .82010.709: 


02510,98771.225 
030i0.9852i.230 
03510.9828). 235 
040i0.9804j.240 
04S!0-978°i-245 


0.8989 1 .425 1 0.8248 1 .62  5 ! 0.7620 1 .825 1 0.7080 
0.8969!  .430]  0.823 1 1 .63010.7605  j .83010.7067 
0.8949 ! .4351 0.82 14!  .635 10.759 1 i .835  i 0.7055 
O.8929!  . 440|0. 8l97|  .640!0.7576l  .840I0.7O42 
0.8909 1 .445  j 0.8 1 80  [ .645 1 o.  7562  j .84  5 ! 0.7030 


°5°!  0.0756!  .250I0.88891 .450I0.8164!  .650J0.7548!  .850)0.7018 
D55j°.9733l -255 1 0.8869). 455)  0.8 147). 655!  0.7533)  .853!  0.7006 
060 1 0.9709 1 . 260 1 0.88  50 1 .460 1 0.8 1 30 1 .660 ! 0.75 191 .860 1 0.6995 
065 1 0.9686!  .265 1 0.8830 1 .465 1 0.81 141 .665 1 0.7505 ! .865 1 0.698  r 
070  j 0.9662 1 .270 1 0.88 1 o j .470  j 0.8098 1 .670  j 0.749 1 1 .870 ' 0.6969 


•075 1 0-9639 1 .275H  0.879 1 1 .475)0.8081 1 -67510.7477'  .875 1 0.6957 
.080  [ 0.96 1 6|  .280  j 0.8772 1 .480 1 0.8065  J .680 ) 0.7463  i .880 1 0.694  5 
•085 1 0.9593 1 -285  i 0.8753  [ .485 10.8049 1 -685 1 0.7449 ! .885 ! 0.6933 
•090lo.9570l.290lo.8734l.490lo.8033l.690lo.7435j.890io.692r 
•O95l0-9547l-295|o-8715[-49sio-8oi6|  .695 10.7422). 895)0.6909 
. 1 00 1 0.95 241 . 300 1 0.8696  . 500 1 0.8000 1 . 700 ! o. 7403 1 .900 ! 06897 
•105  io.9S02 ) .305 1 0.8677  L 505 '0.7984!  .705 10.73941 .905)0.6885 
• t 10)0.9480)  .310I0.86581. 5 10)0.79681. 710)0. 73801. 9100  6873 
•II5l0-94S7l-3i5l0-8639|.5i5lo.7952).7i5lo.7367l.9i5!o.6863 
.■I20lo.9434j.320lo.8621 1.520)0.79371. 720)0.73531.920)0.6850 

. 125  |o.94i2|.325|o.86o2|. 525 10.7921 1.72510. 734o!. 925  !o.6838 
•'30I0.93901. 330j0.8584l.53ol0.7905). 73010.73271.93010  6826 
■135I0.9368I.235I0.85661. 535 10.7890). 735)0.7313). 935)0.6814 
.140I0.93461. 340  t0.8548l.540jo.7874!.  740)0.7300)  .940I0.6803 
•t45i0-9324l-345l°-8529!-545.|o-7859!  •745)0.7286). 945)0.6792 
.150I0.9303I.350I0.8511 1. 550)0.7843!.  750I0.7273I.9500.6780 
- 1 55  I°-928i  1 .355  jo.8493 1 .555 10.782&I  .755 10.7260]  .955)0.6769 
. 160)0.9259 1.360I0.8475I.5601 0.78 1 3 1. 760)0.2747). 96o'o.675~ 
. 1 65 ) 0.9238 1 .365 1 0.8457 1 . 565 1 o.  7798 1 .765 1 o.  7234  i .965 1 0.6746 

. 170)0.92171. 370I0.8439I.570I0.7782]. 770)0.7221  !.970lo.6734 

•• 1 75 ! 0-9196 1 -375 1 0.842 1 1.57510.77671. 775)0.72081. 975'o.672  5 
. [80)0.9175!. 38010.8403!. 58010.7752). 780)0.71951. 980^.671 2 
• '85I0.9I  S4I.385I0.8386!. 585)0.7737!. 785|o.7I82i.985, 0.6701 
. 190)0.91331. 39o|o.8368l.59o|o.7722!.79olo.7i6g,.99o!o  6690 

• ' 95 1 0.9 1 1 2 1 -3951 0-835 1 !•  595 1 07708 1 .795 ) o.  7 1 56 1 .795 1 0.6678 

1 r.  00 '0.6667 


H— 


(54)  Shearing  and  Bearing  value  of  Rivets  in  pounds 
with  © = O. 


Diameter  | 

Iron  Rivets 

Steel  Rivets  i 

Shop  | Field 

Shop  | Field  1 

1 f in.  Rivet.  1 Single  Shear > 1534  | 1227 

| f in.  Rivet.  J in.  Bearing | 1562  1250 

1841  ! 1534 ! 
1875  ! 1562  1 

| f in.  Rivet. 

| f in.  Rivet. 
I f in.  Rivet, 
i # in.  Rivet. 


5-16  in.  Bearing 
§ in.  Bearing.  . . 
7-16  in.  Bearing 
Double  Shear.  . 


! J in.  Rivet. 
| f in.  Rivet. 
! j in.  Rivet, 
j f in.  Rivet. 
I | in.  Rivet, 
f in.  Rive' . 
! | in.  Rivet, 
j f in.  Rivet. 


i i.  in. 
I f in. 

I i in- 

I J in. 
I £ in. 


in, 


! i in. 

I i in. 

I £ in. 
! I in. 


Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 

Rivet. 


| Single  Shear. 

| J in.  Bearing, 

! 5-16  in.  Bearing 
| § in  Bearing.  . . 

| 7-16  in.  Bearing 
| \ in.  Bearing.  . . 

I 9-16  in.  Bearing 
[ Double  Shear.  . 

| Single  Shear.  . . 

! I in.  Bearing.  . . 

! 5-16  in.  Bearing 
I | in.  Bearing.  . . 

I 7-t6  in.  Bearing 
I 4 in.  Bearing.  . . 

I q-t6  in.  Bearing 
I 5 in.  Bearing.  . . 

: it -16  in.  Bearing 
| Double  Shear.  . . 


• I 1953  ! 1562  ! 2344  I 1953  ! 

■ ! 2344  I 1875  | 2812  j 2344 1 
. ! 2734  j 2187 1 3281 1 2734 ; 
. I 3068  I 2454  | 3682  j 3068  | 

. | 2209  | 1767  | 2651  ! 2209  i 
. 1 1875 1 t 500 1 2250  i 1875 1 
1 2344  I T875 1 2812  1 2344  ] 

. ! 2812  | 2250  | 3375  ! 2812  i 
. I 3281  ! 2625  | 3937  1 3281  ; 
. f 3750  I 3000  1 4500  ! 3750  | 

• I 4219  I 3375  I 5062  ! 4219  ! 

• ! 4418 1 3534 1 5302 ! 4418 ; 


! 3006  | 2405  | 3608 
| 2187  I T75°  I 2625 
j 2734 1 2187  | 3281 
| 3281  ! 2625  | 3937 
I 3828  | 3062  | 4593  v 
I 4375  I 35oo  I 5250  I 4375  ! 
j 4922  | 3937.I  5906  ! 4922  | 
| 5469 ! 4-375  ! 6562  ! 5469  i 
I 6015  ! 4812  | 7218  l 6015  ( 
| 6012  I 4810  I 7216  ! 6012  ! 


3006  j 
2187  ! 
2734  I 
3281  ! 
3828  i 


DETAILS  Of 
DESIGN 

Limiiing  Sizes 

Thickness 

Angles 

Bars 

Columns 


Flanges 


Pins 

End  Bearings 
Lead 

Anchors 


Pin  Bearings 


— 15— 

(55)  No  metal  less ‘than  5-16  of  an  inch  thick 
shall  be  used  except  for  fillers.  Web  plates  in  stringers 
beams  and  girders  shall  not  be  less  than  3-8  of  an  inch 
thick. 

(56)  No  angle  weighing  less  than  5 pounds  per 
lineal  foot  shall  be  used. 

(57)  No  bar  having  an  area  of  less  than  1 square 
inch  shad  be  used. 

(58)  The  ratio  of  the  length  of  any  column  to  its 
least  radius  of  gyration  shall  not  exceed  125  for  main 
members  and  150  for  lateral  struts. 

(59)  The  thickness  of  plates  in  columns  shall  not 
be  less  than  1-40  of  the  distance  between  supports  in 
a direction  at  right  angles  to  the  line  of  stress  and  not 
less  than  1-16  of  the  distance  between  supports  or  rivets 
in  the  line  of  stress. 

(60)  Beams  and  girders  having  a length  greater 
than  16  times  the  width  of  the  flange  shall  be  braced 
horizontally. 

(61)  The  diameter  of  no  pin  shall  be  less  than  3-4 
of  the  width  of  the  widest  bar  attached  to  the  same. 

(62)  Sheet  lead  not  less  than  1-8.  of  an  inch  in 
thickness,  shall  be  interposed  between  ad  bearing  plates 
and  masonry. 

(63)  All  bearings  shall  be  thoroughly  and  effi- 
ciency anchored  to  the  masonry  by  means  of  bolts,  not 
less  than  1 1-4  inches  in  diameter,  set  at  least  12  inches 
into  the  masonry  with  neat  Portland  cement  mortar. 

(64)  To  insure  a more  even  bearing  on  the  ma- 
sonry, spans  of  80  feet  or  more  in  length  shall  have  pin 
end  bearings.  Cast  steel  pedestals  will  be  preferred  for 
plate  girder  spans. 


— 16— 


Sliding  Ends 


Roller  Ends 


Pin  Plate 


Camber 

Trusses 


(65)  Spans  less  than  75  feet  in  length  may  have 
sliding  plates  at  one  end  of  the  span  to  allow  for  ex- 
pansion  and  contraction  due  to  a change  in  temperature 
of  150  degrees  Fahrenheit.  Each  bearing  shall  consist 
of  two  plates,  an  upper  or  shoe  plate  and  a lower  or  ma 
sonry  plate.  Both  shoe  and  masonry  plates  shall  be 
planed,  and  the  joint  between  the  two  plates  shall  be 
planed  with  tongue  and  groove  for  both  fixed  and 
sliding  ends  of  the  span.  The  finished  thickness  of  the 
plates  shall'  not  be  less  than  3- 4 of  an  inch.  The  anchor 
bolt  holes  in  the  shoe  plates  on  the  sliding  end  must  be 
slotted  to  allow  for  expansion  and  contraction. 

(66)  One  end  of  all  spans  of  75  feet  or  more  in 
length  shall  have  roller  end  bearings  to  permit  free  ex- 
pansion and  contraction,  due  to  a change  in  temperature 
of  150  degrees  Fahrenheit. 

(67)  The  rollers  shall  not  be  less  than  3 inches  in 
diameter,  shall  be  turned  with  a groove  at  the  center, 
and  shall  travel  between  shoe  and  masonry  plates,  each 
of  which  shall  be  planed  with  a tongue. 

(68)  All  rollers  of  a single  bearing  shall  he  joined 
by  spacing  bars  at  their  ends.  All  roller  bearings  shall 
have  guards  to  protect  them  from  dirt  and  shall  be 
made  accessible  for  cleaning. 

(69)  For  heavy  or  long  spans,  segmental  rollers 
and  a masonry  plate,  built  up  of  railroad  rails,  and  a 
plate  will  be  preferred. 

(70)  On  piers,  the  masonry  plate  shall  be  con- 
tinuous, extending  under  both  bearings  of  contiguous 
spans. 

(71)  All  trusses  shall  have  just  sufficient  camber 
so  that  under  a full  load  the  truss  will  come  to  a level 


-17- 


Plate  Girders 


Framing  Out 


Rivets 


Net  Section 


Rolled  Beams 


Built  Beams 


Flanges 


line.  This  will  be  accomplished  by  shortening  each  ten- 
sion member  and  lengthening  each  compression  mem- 
ber by  an  amount  equal  to  the  change  in  length  of  that 
member  under  full  load. 

(72)  Plate  girders  shall  be  given  a camber  equal 
to  one  one-thousandth  of  the  span. 

(73)  One-half  of  the  camber  shall  be  framed  out 
in  the  beams  and  stringers,  and  the  ther  half  in  the 
ties. 

(74)  Rivets  shall  generally  be  3-4  and  7-8  of  an  inch 
in  diameter,  they  shall  be  spaced  at  least  3 diameters  apart 
and  except  in  lacing  bars  their  centers  shall  not  be  nearer 
the  edge  of  any  member  through  which  they  pass  than  1 
1-4  inches.  No  rivet  shall  have  a grip  exceeding  five  times 
its  diameter. 

(75)  The  net  section  of  any  tension  member  or  flange 
shall  be  determined  by  a plane  cutting  the  member  square 
across  at  any  point.  The  greatest  number  of  rivet  holes 
which  can  be  cut  by  the  plane  or  whose  centers  come  within 
one  inch  of  the  plane,  is  the  number  to  be  deducted  from 
the  gross  sectio  . 

(76)  Rolled  Beams  shall  be  proportioned  for  bending 
stresses  in  accordance  with  their  moments  of  inertia. 

(77)  Built  beams,  used  for  stringers,  floor  beams  or 
girders,  shall  be  proportioned  in  accordance  with  the  fol- 
lowing assumptions : 

(78)  It  shall  be  assumed  that  the  bending  stresses 
are  resisted  entirely  by  the  flange  section.  No  part  of 
the  web  plate  shall  be  assumed  as  effective  for  flange 
section. 


(79)  Flanges  shall  be  proportioned  from  the 


— 1 8— 


Web  Plate 

tension  stresses,  and  the  compression  flange  shall  have 
the  same  gross  section  as  the  tension  flange. 

(80)  It  shall  be  assumed  that  all  the  shear  is  car- 
ried by  the  web  plate. 

Effective  Depth 

(81)  The  effective  depth  shall  be  the  distance  be- 
tween centers  of  gravity  of  the  flanges  except  when  this 
exceeds  the  distance  out  to  out  of  flange  angles.  In  no 
case  shall  the  effective  depth  be  taken  at  more  than  the 
distance  out  to  out  of  flange  angles. 

Flange  Splices 

(82)  So  far  as  possible,  splices  in  the  flanges  shall 
be  avoided.  When  splices  become  necessary,  all  joints 
must  be  fully  spliced,  all  abutting  surfaces  must  be 
machine  finished  and  must  be  brought  into  perfect  con- 
tact in  assembling.  In  the  tension  flanges,  sufficient 
section  must  be  provided  in  the  splices  to  make  up  for 
all  lost  section  in  the  member  spliced. 

Web  Splices 

(83)  Splices  in  web  plates  shall  be  made  at  points 
where  stiffeners  occur,  and  shall  be  made  with  a plate 
on  each  side  of  the  web,  wide  enough  to  take  two  rows 
of  rivets  on  each  side  of  the  splice.  The  splice  plates 
shall  not  be  thinner  than  the  web  itself. 

Stiffeners 

(84)  When  the  unit  shear  on  the  web  plate  ex- 
ceeds that  allowed  by  the  formula 

o noh 

S=i  1000 — ~y 

stiffeners  shall  be  used. 

Note):- — S *=  Allowed  shear  in  pounds  per  square 

inch. 

h = Unsupported  height  of  web  in  inches. 

t = Thickness  of  web  in  inches. 

See  curves  in  appendix. 

-19— 


(85)  Stiffeners  shall  consist  of  a pair  of  angles, 
one  on  each  side  of  the  web  and  they  shall  be  spaced 
at  intervals,  about  equal  to  the  depth  of  the  girder. 

(86)  The  size  of  the  stiffener  angles  shall  be  as 
follows,  depending  upon  the  width  of  the  horizontal 
ieg  of  flange  angles : 

For  an  8 inch  leg  use  6x3  1-2  x 3-8  angles. 

For  an  7 inch  leg  use  6x3  1-2  x 3-8  angless. 

For  a 6 inch  leg  use  5x3  1-2  x 3-8  angles. 

For  a 5 inch  leg  use  4 x 3 x 3-8  angles. 

For  a 4 inch  leg  use  3 x 3 x 3-8  angle. 

(87)  A pair  of  stiffeners  shall  be  used  over  each 

end  of  each  end  bearing,  and  when  pin  bearings  are 
used,  there  shall  be  an  additional  pair  over  the  center  of 
each  bearing. 

(88)  Fillers,  equal  in  thickness  to  the  flange  angles, 
shall  be  used  under  all  stiffeners,  except  at  splice  po’nts 
where  the  splice  plates  serve  for  fillers. 

(89)  When  side  plates  are  used  under  the  flange 
angles,  the  fillers  shall  be  of  the  same  thickness  as  the 
side  plates,  and  the  stiffeners  may  be  crimped  over  the 
flange  angles. 

(90)  The  pitch  of  rivets  uniting  the  flange  angles 
to  the  web  plate  shall  not  exceed  that  given  by  the  for- 
mula : 

p = r d -4-  s 

where  p = Pitch  of  rivets 

r = Value  of  one  rivet 

d = Distance  between  rivet  lines 

s = Shear  at  the  point  under  consideration. 


-30 


(91)  The  pitch  of  rivets  between  stiffeners  shall 
be  uniform,  and  shall  be  determined  from  the  shear  at 
the  siffener  nearer  the  end  of  the  girder,  but  in  no  case 
shall  the  pitch  of  rivets  in  each  gauge  line  exceed  9 
inches. 

krac‘n£  (92)  Deck  girders  less  than  30  feet  in  length,  shall 

be  braced  in  the  plane  of  the  top  flanges,  and  shall 
have  cross  frames  at  ends  and  at  intermediate  pouits. 
Deck  girders  30  feet  or  more  in  length  shall  have  top 
and  bottom  bracing,  and  cross  frames  at  the  ends  and  at 
intermediate  points.  The  bracing  shall  generally  take 
the  form  of  a Warren  truss,  the  diagonal  members  in 
the  top  system  being  made  of  two  angles  back  to  back, 
and  in  the  bottom  system,  of  a single  angle.  This  di- 
agonals in  the  cross  frames  shall  consist  of  two  angles 
in  each  direction,  the  top  and  bottom  horizontals  of  two 
angles  for  the  end  frames,  and  of  one  or  two  angles  for 
the  intermediate  frames  as  may  be  required.  All  angles 
shall  be  connected  at  their  ends  so  as  to  develope  their 
full  strength. 

(93)  Through  girders  shall  have  one  set  of  ad- 
justable, horizontal,  lateral  bracing,  generally  using  the 
floor  beams  for  struts.  The  floor  beams  shall  be  at- 
tached to  the  main  girders  through  gusset  plates  ex- 
tending the  full  depth  of  the  girders.  When  the  gus- 
set plate  extends  more  than  96  times  its  thickness  above 
or  below  the  beam,  there  shall  be  two  3x2  1-2  inch 
angles  riveted  to  its  edge. 

End  Finish 

(94)  All  through  girders  shall  have  their  upper 
corners  rounded  and  the  first  flange  plate  shall  extend 
down  to  the  bottom  of  the  girder. 

(95)  The  ends  of  all  deck  girders  shall  be  covered 


Ends  Faced 


Pin-connected 

Bridges 

Compression 

Members 


Battens 


Lattice 


with  a p!ate  riveted  to  the  end  stiffener  angles,  and  in 
addition,  there  shall  be  corner  cover  plate  riveted  over 
each  upper  corner  of  the  girder. 

(96)  When  the  detail  will  permit,  the  ends  of  all 
stringers  and  floor  beams  shall  be  faced  and  extra  ma- 
terial must  be  provided  in  the  end  angles  to  allow  foi 
planing. 

(97)  End  post  and  top  chord  sections  shall  gen- 
erally consist  of  two  rolled  or  built  channels,  joined  on 
their  upper  flanges  by  a cover  plate,  and  on  their  lower 
flanges  by  batten  plates  near  the  ends  and  diagonal 
lattice  bars  between  the  battens. 

(98)  Intermediate  posts  shall  generally  consist 
of  two  rolled  or  built  channels  joined  on  both  flanges 
by  battens  near  the  ends,  and  diagonal  lattice  bars  be- 
tween the  battens. 

(99)  The  length  of  the  batten  plate  shall  not 
be  less  than  the  greatest  width  of  the  member  and. 
its  thickness  shall  not  be  less  than  T-40  of  its  un- 
supported width.  No  batten  shall  have  less  than 
three  rivets  along  each  edge. 

(100)  Lattice  bars  shall  have  a width  of  at 
least  three  diameters  of  the  rivet  and  a thickness 
of  at  least  1-50  of  the  unsupported  length.  The 
spacing  of  the  bars  shall  be  such  that  the  angle  be- 
tween the  bar  and  the  center  line  of  the  section 
shall  not  be  less  than  60  degrees,  for  single  lattice 
and  45  degrees  for  double  lattice  and  the  distance 
between  rivets  in  either  channel  flange  shall  not 
exceed  60  times  the  thickness  of  the  flange. 
Double  lattice  bars  shall  have  a rivet  at  each  inter- 
section. On  large  or  wide  sections,  3x2  inch  an- 
gles shall  be  used  instead  of  bars  for  lattice. 


22 


Ri  ve  ling; 


Pin-plates 


Pin-holes 


Splices 


Eyebars 


( idi ) At  each  end  of  any  compression  mem- 
ber for  a distance  equal  to  twice  its  width  the 
pitch  of  the  rivets  shall  not  exceed  four  diameters 
of  the  rivet  and  throughout  the  remaining  portion 
of  the  member  the  pitch  shall  net  exceed  6 inches 
or  1 6 times  the  thickness  of  the  thinnest  plate  or 
angle. 

(102)  Where  necessary  pin  holes  shall  be  re- 
inforced by  pin  plates.  At  points  where  the  stress 
is  transmitted  entirely  to  the  pin,  the  first  pin  plate 
shall  extend  back  from  the  pin  far  enough  to  over- 
lap the  batten  plate  by  at  least  6 inches. 

(103)  When  computing  the  necessary  num- 
ber of  rivets  for  the  pin  plate,  the  bearing  per 
square  inch  between  the  pin  and  pin  plate  shall 
be  assumed  the  same  as  between  the  pin  and  main 
member. 

(104)  Pin  holes  shall  be  placed  with  ref- 
erence to  the  center  of  moments  of  the  section  and 
they  shall  be  placed  enough  below  that  center  to 
balance  the  bending  moment  due  to  the  weight  of 
the  member. 

(105)  Splices  in  the  top  chord  shall  gener- 
ally be  made  a short  distance  from  the  pin  point 
and  all  splices  shall  be  equiped  with  splice  plates 
and  cover  plates  to  hold  the  members  truly  in  po- 
sition. 

(106)  The  main  diagonal  and  bottom  chord 
members  shall  be  made  of  die  forged  eyebars,  con- 
structed in  such  a way  that  when  tested  to  destruction 
they  will  break  in  the  main  body  of  the  bar  rather  than 
in  the  head. 


Stiffened 

Sections 


Adjustable 

Members 


Stringers 


•Beams 


Bracing 


Top  Struts 


Knees 


Cross  Bracing 


Portals 


—23— 

(107)  The  first  two  panels  of  bottom  chord  at 
each  end  of  the  span  and  the  hip  verticals  or  long  sus- 
penders shall  be  stiffened.  These  members  may  be 
laced  eyebars. 

(108)  All  counters  and  lateral  rods  shall  be  ad- 
justable by  means  of  open  turnbuck'es  or  devices. 
The  threaded  ends  of  all  rods  must  be  upset.  The 
ends  of  all  rods  attached  to  pins  shall  have  loop  eyes 
with  the  distance  from  the  back  of  the  pin  to  the  apex 
of  the  loop  not  less  than  three  diameters  of  the  pin. 

Only  iron  bars  may  have  loop  eyes. 

(109)  The  stringers  shall  preferably  be  framed 
in  between  the  floor  beams ; if  placed  on  top  they  shall 
have  a cross  frame  at  each  end. 

( 1 10)  The  floor  beams  shall  be  built  in  between 
the  posts  of  the  main  trusses  and  shall  be  connected 
to  the  same  through  gussets  extending  at  least  3 feet 
above  the  top  of  the  beam. 

(hi)  All  pin  connected  bridges  shall  have  ad- 
justable bracing  in  the  planes  of  the  top  and  bottom 
chords  and  as  near  as  practicable  to  the  pin  center  lines. 

( 1 12)  The  top  struts  shall  generally  be  made 
of  four  angles  laced  the  full  depth  of  the  ch?rd. 

(113)  When  the  distance  from  rail  to  top 
strut  does  not  exceed  25  feet,  knee  braces  shall  be 
used  connecting  the  top  struts  to  the  vertical  posts 
of  the  main  trusses. 

( 1 14)  When  the  distance  from  rail  to  top  strut 
exceeds  25  feet,  sub-struts  and  cross-bracing  shall 
be  used  instead  of  knee  braces. 

( 1 15)  The  end  posts  shall  be  connected  by 
portal  struts,  so  designed  as  to  effectively  transmit 


24- 


Viaducts  or 

Trestles 

Type 

Bents 

Towers 

Rocker 

Batter 

Bearings 


Anchorage 


Bracing 


the  wind  stresses  from  the  top  lateral  system  to 
the  bridge  seat.  Portals  shall  be  as  deep  as  the 
specified  clearance  will  permit  and  brackets  usual- 
ly curved,  shall  be  used  connecting  the  bottom 
flange  of  the  portal  strut  to  the  end  posts. 

(116)  Viaducts  shall  generally  consist  of  plate 
or  open  web  riveted  girders,  supported  by  bents  and 
towers. 

( 1 17)  A bent  consists  of  a pair  of  columns  braced 
transversely. 

(118)  A tower  consists  of  two  bents  braced 
longitudinally. 

(119)  When  a bent  is  used  separately  it  shall  be 
designed  as  a rocker  and  shall  have  pin  ends  at  top  and 
bottom. 

(120)  Each  column  in  a bent  shall  have  a batter 
of  not  less  than  one  horizontally  to  six  vertically. 

(121)  Provision  shall  be  made  at  the  foot  of  each 
bent  for  expansion  and  contraction  due  to  changes  in 
temperature  of  150  degrees  Fahrenheit.  All  sliding 
surfaces  shall  be  planed  and  anchor  bolt  holes  slotted 

(122)  All  bents  and  towers  shall  be  anchored  to 
the  foundations  in  such  a way  as  to  be  safe  against 
overturning  whether  loaded,  unloaded  or  loaded  with 
empty  cars. 

(123)  When  a viaduct  is  located  on  a curve,  the 
effects  of  centrifugal  force  must  be  considered:  in  addi- 
tion to  the  wind  loads. 

(124)  Transversely  all  bents  shall  be  braced 
with  angles  against  all  efifects  of  wind  and  centrifugal 
force.  Longitudinally  all  towers  shall  be  braced  with 


Swing  Bridges 
Floor  System 


Trusses 


Turntable 


Disc  Center 


Roller  Center 


-25- 

angles  or  channels  against  the  effects  of  stopping  a train 
on  the  viaduct.  Transverse  struts  shall  be  used  at  the 
bottom  of  a*  1 bents  and  longitudinal  struts  at  the  bot- 
tom of  all  towers  strong  enough  to  slide  the  columns 
when  changes  in  temperature  occur. 

(125)  The  floor  system  of  swing  bridges  shall 
be  designed  the  same  as  for  fixed  spans. 

(126)  Wffh  the  bridge  closed,  the  trusses  shall 
be  designed  under  the  same  unit  stresses  as  for  fixed 
spans,  but  with  the  bridge  open  the  dead  load  unit 
stresses  shad  not  exceed  three-quarters  of  the  dead  load 
unit  stresses  for  fixed  spans. 

(127)  The  turntable  may  be  center  bearing,  rim 
bearing  or  a combination  of  the  two.  If  the  combina- 
tion table  is  used  the  supporting  girders  shall  be  so  ar- 
ranged that  some  definite  and  known  portion  of  the 
load  will  be  carried  to  the  center. 

(128)  When  a disc  center  is  used  there  shall 
be  three  discs,  the  upper  and  lower  of  hard  steel 
and  the  center  of  phosphor  bronze,  and  so  arrang- 
ed that  all  sliding  will  occur  between  the  steel  and 
phosphor  bronze  discs.  The  discs  shall  have  oil 
grooves  and  the  center  shall  be  so  arranged  that 
the  discs  may  be  kept  flooded  with  oil. 

(129)  When  a roller  center  is  used  the  roll- 
ers shall  be  turned  truly  conical  and  shall  be  pro- 
vided with  a band  to  ho’d  them  in  position.  All 
rollers  shall  be  of  hard  steel  and  will  travel  be- 
tween tracks  of  hard  steel,  planed  to  a true  bevel  to 
fit  the  rollers.  The  center  shall  be  so  arranged 
that  the  rollers  may  be  kept  flooded  with  oil. 


— 26— 


f&m  Bearing; 


LatdfcS 


End  Lifts 


(130)  When  a rim  bearing  table  is  used,  the 
load  shall  be  conveyed  by  means  of  a circu  ar  drum 
to  a set  of  cast  steel  wheels  turned  truly  conical 
which  travel  between  two  steel  tracks,  one  above 
attached  to  the  drum  and  one  below  attached  to  the 
foundation.  The  tracks  shall  be  planed  circular 
and  to  a true  bevel  to  fit  the  wheels. 

(131)  The  bottom  track,  wheels  afid  drum 
shall  be  connected  to  an  iron  casting  at  the  center 
of  the -table  in  order  to  keep  all  properly  centered. 
The  drum  shall  be  connected  by  means  of  radial 
struts  to  a hub  which  is  free  to  rotate  about  the 
center  casting.  The  wheels  shall  be  connected  by 
means  of  spider  rods  to  another  similar  hub. 

(132)  There  shall  be  two  circular  bands  to 
keep  the  wheels  properly  spaced  one  inside  and 
the  other  outside  the  wheels.  The  outer  band 
shall  be  made  in  short  sections  so  arranged  that 
any  wheel  may  be  easily  removed  and  replaced 
without  disturbing  the  others.  Each  spider  rod 
shall  extend  through  a wheel  and  both  bands  and 
shall  be  provided  with  nuts  and  washers  making 
it  possible  to  adjust  the  conical1  wheels  to  a shorter 
or  longer  radius. 

(133)  Both  ends  of  the  bridge  shall  be  provided 
with  strong  latches  arranged  to  close  automatically  and 
to  be  opened  from  the  tender’s  house. 

(134)  End  lifts  shall  be  provided  for  raising 
both  ends  of  the  bridge  by  an  amount  sufficient  to  pre- 
vent the  lifting  of  either- end  clear  from  its  seat  under 
any  position  of  the  load.  They  shall  be  so  arranged 
that  they  may  be  operated  from  the  tender’s  house. 


Kail  Lifts 


End  Signals 


Machinery 


Cables 


Motors 


Material 


Tender’s  House 


—27— 

(135)  Both  ends  of  the  bridge  shall  be  equipped 
with  suitable  rail  lifts  arranged  to  be  operated  from 
the  tender’s  house. 

( 136)  At  each  shore  end  of  the  bridge  there  shall 
be  an  automatic  signal  so>  arranged  that  the  bridge 
cannot  be  opened  without  setting  the  signal  to  the 
position  of  danger. 

( 1 37)  Under  this  head  shall  be  included  all  mo- 
tors, cables,  wires,  switches,  controllers,  lightening  ar- 
resters. electric  heaters,  gears,  shafting,  rack  and  such 
other  equipment  as  is  necessary  to  make  a complete  and 
perfect  plant  for  the  operation  of  the  bridge  by  both 
hand  and  electric  power. 

(138)  The  necessary  sub-marine  cables  shall 
be  furnished  by  the  Contractor  for  the  superstruc- 
ture, but  shall  be  put  in  place  by  the  Contractor  for 
the  substructure. 

(139)  The  motor  for  turning  the  bridge 
shall  be  of  sufficient  capacity  to  turn  the  bridge 
through  a quadrant  in  one  minute,  starting  from 
rest  and  ending  at  rest. 

( 140)  The  motors  for  operating  the  end  lifts, 
rail  lifts  and  end  signals  may  be  placed  at  the  ends 
of  the  bridge. 

(141)  All  shafting  shall  be  medium  steel, 
all  pinions,  gears,  rack  and  shaft  bearings  shall 
be  cast  iron  or  cast  steel.  All  shaft  bearings  shall 
be  babbitted. 

(142)  A tender’s  house  of  neat  design  shall  be 
provided  at  the  center  of  the  bridge,  preferably  over  the 
track,  in  which  all  controllers,  switches,  lightening 
arresters,  heaters  and  other  electric  equipment  shall  be 


— 2g— 


Shop  work 

Fifst  Class 


Straightening 


Punching 


Reaming 


Drilling 


Riveting 


placed.  When  necessary  a stairway  shail  he  provided 

for  the  tender’s  house. 

(143)  All  shop  work  shall  he  first  class  in  every  par- 
ticular. 

(144)  When  necessary  all  material  shall  be  straight- 
ened before  being  laid  ofb.  After  punching  and  before  as- 
sembling all  material  shall  be  carefullv  straightened  and 
freed  from  all  twists  and  buckles.  A'l  web  plates  must  be 
free  from  buckles. 

( t45 ) All  straightening  shall  be  done  in  presses  of 
between  rolls.  Hammering  will  not  be  allowed. 

(146)  All  punched  holes  shall  be  made  with  a punch 
one-eighth  of  an  "nch  smaller  in  diameter  than  the  rivet. 
The  die  shall  not  be  more  than  one-sixteenth  of  an  inch 
greater  in  diameter  than  the  punch. 

(147)  After  punching  and  assembling  all  punched 
holes  shall  be  reamed  to  a diameter  not  more  than  one-six 
teenth  of  an  inch  greater  than  the  diameter  of  the  cold  rivet. 
After  reaming  all  holes  shall  be  smooth,  showing  that  nietal 
has  everywhere  been  removed  around  the  hole. 

(147)  When  any  metal  is  too  tlr’ck  for  successful 
punching,  all  holes  shall  be  drilled.  All  rivet  holes  in  eve- 
bars  shall  be  drilled  and  all  pin  holes  shall  be  drilled  or 
bored. 

(149)  All  shop  rivets  so  far  as  possible  shall  be  driven 
with  a machine  capable  of  holding  the  pressure  after  the 
rivet  is  driven.  All  rivets  shall  be  driven  tight  and  upset 
so  as  to  completely  fill  the  hole.  No  calking  or  cupping  will 
be  allowed.  Rivets  of  the  same  size  shall  have  the  sqme  size 
heads  and  the  heads  must  be  concentric  with  the  rivet.  All 
loose  or  poor  rivets  must  be  cut  out  and  replaced. 


—29- 


Facing 


Fitting 


Planing 


Pin  Holes 


Lathe  Work 


Eye-bars 

Material 

Heads 


(150)  The  ends  of  all  beams  and  stringers,  when 
built  in.  shall  be  faced  square  and  true  to  length. 

( 1 5 1 ) Abutting  ends  of  all  compression  members 
shall  be  faced  in  a machine  so  that  their  ends  will  be  in  per- 
fect contact  when  in  pi  ace  in  the  bridge. 

(152)  The  ends  of  all  stiffenerj  shall  be  trimmed  to 
fit  tight  against  the  flange  angles  and  all  fillers  under  the 
stiffeners  shall  be  made  to  fit  tight  against  the  edges  of  the 
flange  angles. 

(153)  All  abutting  ends  of  web  plates  for  plate  gird- 
ers shall  be  planed. 

(154)  The  edges  of  all  sheared  plates  shall  be  planed. 

(155)  All  shoe  and  masonry  plates  shall  be  planed  so 
that  the  two  faces  of  each  plate  are  truly  parallel. 

(156)  Pin  holes  in  riveted  members  shall  be  bored 
truly  parallel  to  each  other  and  at  right  angles  to  the  axis 
of  the  member. 

(157)  Pin  holes  in  eyebars  must  be  in  the  axis  of  the 
bar,  in  the  center  of  the  heads  and  at  right  angles  to  the 
planes  of  the  flat  surfaces.  When  all  the  bars  of  the  same 
member  are  piled  together,  the  pins  shall  pass  through  both 
ends  of  all  bars  without  driving. 

(158)  The  diameter  of  the  pin  hole  shall  not  exceed 
that  of  the  pin  by  more  than  1-50  of  an  inch  except  for 
pins  over  4 inches  in  diameter  when  this  excess  shall  not 
exceed  1-32  of  an  inch. 

(159)  All  pins  and  rollers  shall  be  turned  smooth  and 
true  to  £ize. 

(160)  All  eyebars  shall  be  made  from  bars  of  full 

section  and  free  from  folds,  cracks,  or  other  defects. 

(161) -  The  heads  shall  be  made  by  upsetting  and 

forging  the  bars.  No  head  shall  be  more  than  one-six- 


Annealing 

Adjustable  Rods 
Loop  Eyes 


Upsettirg 


Annealing 

Painting 

Cleaning: 

Before 

Assembling 

inaccessible 

Parts 

Machined 

Surfac«s 


So— 

teenth  of  an  inch  thicker  than  the  body  of  the  bar.  All 
heads  shall  be  so  proportioned  and  made  that  the  bars 
will  break  in  the  body  of  the  original  bar  and  not  in  the 
head  or  neck. 

(162)  After  the  heads  are  Completed  the  bars 
shall  be  annealed  by  being  heated  to  a bright  red  heat 
throughout  their  entire  length  and  then  allowed  to  cool 
slowly. 

(163)  The  ends  of  all  rods  attached  to  pins  shall 
have  loop  eyes  formed  by  bending  the  bar  around  a pm 
and  weMing  the  end  to  the  main  body  of  the  bar.  All 
loop  eyes  shall  have  holes  bored  to  fit  the  pin.  Only 
iron  bars  may  have  loop  eyes. 

(164)  The  ends  of  all  rods  that  take  nuts,  turn- 

buckles  of  devices  shall  have  their  ends  enlarged  by 

upsetting  the  bar.  The  cross-sectional  area  of  the 

upset  end  at  the  root  of  the  thread  shall  be  at  least  10 

per  cent,  greater  than  the  original  area  of  the  bar  and 

under  test  to  destruction  the  bar  must  break  in  the 
» 

main  body  and  not  in  the  upset  end. 

(165)  Steel  bars  with  upset  ends  shall  be  an- 
nealed the  same  as  eyebars.  See  paragraph  162. 

(166)  All  material  shall  be  thoroughly  cleaned 
from  dirt  rust  and  Scale  before  any  oil  or  paint  is  ap-. 
plied.  Wire  brushes  and  steel  scrapers  shall  be  used 
when  necessary. 

(167)  All  surfaces  Coming  in  contact  shall  have 
one  coat  of  red  lead  paint  before  assembling. 

(168)  All  parts  not  accessible  after  erection  shail 
have  two  coats  of  red  lead  paint. 

(169)  All  machine  finished  surfaces  shall  have 
a coat  of  white  lead  and  tallow  before  shipment. 


Other  Parts 


— 31— 


(170)  All  other  parts  shall  have  one  coat  of  boil- 
ed linseed  oil  before  shipment. 

Application  (171)  No  oil  or  paint  shall  be  applied  in  wet 

or  freezing  weather,  or  when  the  metal  is  not  dry,  and 
no  coat  shall  be  applied  until  the  one  before  is  thor- 
oughly dried.  No  material  shall  be  painted  until  after 
it  has  been  examined  and  accepted  by  the  inspector. 

(172)  All  oil  and  paint  shall  be  applied  with 
good  thick  brushes  (round  preferred)  with  elastic 
bristles,  by  skilled  painters  and  shall  be  thoroughly 
brushed  out  and  worked  into  all  open  spaces  and  so 
applied  as  to  completely  cover  the  surface. 

(173)  All  oil,  when  applied,  shall  be  heated  to  a 
temperature  of  from  150  to  200  degrees  Fahrenheit. 

(174)  All  red  lead  paint  shall  be  kept  well  stirred 
while  it  is  being  used. 


FIELD  WORK 
Ready  for  Rails 


Floor  Deck 


Falsework 


Interrupting 

Traffic 


(175)  Unless  otherwise  specified  all  bridges  shall  be 
erected  by  the  Contractor  ready  for  the  rails. 

(176)  All  rail.;,  splices  and  fastenings  for  the  same 
shall  be  furnished  and  put  in  place  by  the  "Railway  Company ; 
all  ties  and  guard-rails  shall  be  furnished,  delivered  at  the 
bridge  site,  by  the  Railway  Company,  but  will  be  put  in  place 
by  the  Contractor,  all  floor  deck  bolts,  washers,  nut  locks, 
etc.,  being  furnished  by  the  Contractor.  See  paragraphs  18 
to  21  inclusive. 

(177)  All  falsework  timber,  bolts,  etc.,  shall  be  fur- 
nished and  put  in  place  by  the  Contractor  and  shall  be  re- 
moved by  him  after  completion  of  the  work. 

(178)  When  a bridge  is  being  erected  on  a line  al- 
ready in  operation,  the  work  shall  be  done  without  inter- 
rupting traffic,  except  as  arrangements  are  made  for  such 
interruption. 


Renewal 


Anchorage 


Watchmen 


Laws 


Risks 


Reaming 


Riveting 


turned  Bolts 


hlot  Nuts 


Fainting 

Cleaning 


Rivet  Heads 


(179)  In  case  of  a renewal  the  Contractor  shall  take 
down  the  old  bridge  and  pile  the  same  on  the  bank  or  load 
it  on  cars  as  may  be  directed. 

(180)  The  Contractor  shall  drill  all  the  necessary  aria 
chor  bolt  holes  in  the  masonry,  and  shall  set  the  bolts  in 
place,  fastening  the  same  with  neat  Portland  cement  mortar. 

(181)  When  necessary  the  Contractor  shall  provide 
Watchmen  and  other  safeguards  during  erection. 

(182)  The  Contractor  shall  comply  with  all  laws  and 
ordinances  whenever  there  are  any  applicable  to  the  work  it! 
execution. 

(183)  The  Contractor  shall  assume  all  risks  of  acci- 
dents or  from  floods  or  other  causes  until  the  final  comple- 
tion of  the  work.  / 

(184)  When  assembling  the  Work  in  the  field,  any 
inaccuracies  in  the  rivet  holes  must  be  corrected  by  reaming, 
drifting  will  not  be  allowed.  Drift  pins  may  only  be  used  to 
bring  the  pieces  together. 

(185)  All  rivets  must  have  full  heads,  concentric  with 
the  rivet,  of  a uniform  size  for  the  same  size  of  rivet  and 
must  be  driven  so  as  to  Completely  fill  the  holes.  Loose  or 
poor  rivets  must  be  cut  out  and  replaced. 

(186)  Where  it  is  impossible  to  drive  rivets  in  the 
field,  turned  bolts  may  be  ttSed  provided  they  are  turned  to  a 
driving  fit. 

(187)  Pilot  nuts  shall  be  used  on  pins  to  protect  the 
threads  when  the  pins  are  being  driven. 

(188)  Before  applying  the  field  coats  of  paint,  all 

members  shall  be  cleaned  from  all  blisters,  loose  paint 

and  dirt. 

(189)  After  erection  and  before  applying  the 


First  Coat 

Second  Coat 

Application 


QUALITY 
OF  MATERIAL 

Wrought  steel 

Process 

Finish 

Variation 


—33— 

finishing  coats  all  heads  of  field  rivets  shall  he  painted 
with  the  same  material  as  used  for  the  first  field  coat. 

(190)  After  erection  all  accessible  parts  shall  re- 
ceive one  coat  of  “Red  Lead  Metal  Preservative.” 

(191)  After  the  “Red  Lead  Metal  Preservative” 
is  thoroughly  dry  all  accessible  parts  shall  receive  a 
second  field  coat  which  shall  be  a high  grade  graphite 
or  carbon  paint. 

(192)  No  paint  shall  be  applied  in  wet  or  freez- 
ing weather,  or  when  the  metal  is  not  dry.  All  paint 
shall  be  applied  with  good  thick  brushes  (round  pre- 
ferred) having  elastic  bristles  and  by  skilled  painters. 
All  paint  must  be  well  rubbed  onto  the  surface  and 
worked  into  all  open  spaces  and  so  applied  as  to  com* 
pletelty  cover  the  surface. 

(193)  All  wrought  steel  shall  be  made  by  the 
Open  hearth  process. 

(194)  The  finished  product  shall  be  true  to  size 
and  shape  and  free  from  imperfections  such  as  cracks 
or  roughness.  When  two  or  more  universal  mill 
plates  of  the  same  width  come  together  in  the  finished 
work  they  must  be  of  uniform  width  and  their  edges 
must  not  be  beveled. 

(195)  No  greater  variation  than  2j  per  cent,  shall 
be  allowed  between  the  estimated  and  actual  weight  of 
any  piece  of  material  except  for  wide  plates  where  the 
actual  weight  may  exceed  the  estimated  weights  by  the 
amounts  given  in  the  following  table : 


Phosphorus 


Test  Pieces 


Ultimate 

Strength 


—34— 


Thickness 

Width 

of 

Plate  in  Inches. 

in  Inches. 

48  to  75  I 

_75 

to  100.  | 

Ovrer  100. 

IH  [ 

10  per  cent. 

14 

per  cent.  | 

18  per  cent. 

5-i6  l 

8 per  cent.  | 

12 

per  cent.  | 

16  per  cent. 

■3-8  1 

7 per  cent,  i 

10 

per  cent. 

13  percent. 

7-16  1 

6 per  cent. 

9 

per  cent. 

10  per  cent. 

1-2  | 

5 per  cent.  | 

7 

per  cent. 

9 per  cent. 

9-16  1 

4\  per  cent,  j 

64 

per  cent,  j 

84  per  cent. 

5-8  | 

4 per  cent.  1 

6 

per  cent. 

8 per  cent. 

Over  5-8  | 

3-|-  per  cent.  | 

5 

per  cent. 

64  per  cent. 

(196)  The  amount  of  phosphorus  shall  not  ex- 
ceed .08  per  cent,  in  steel  made  in  an  acid  furnace  and 
.04  per  cent,  in  steel  made  in  a basic  furnace. 

(197)  The  properties  of  steel  shall  be  determin- 
ed from  test  prices  cut  from  the  finished  product,  rep- 
resenting each  melt. 

(198)  The  test  pieces,  about  12  inches  long,  shall 
be  planed  or  turned  to  a uniform  area  of  not  less  than 
4 of  a square  inch  for  a length  of  10  inches. 

(199)  Pieces  representing  annealed  bars  may  be 
annealed  before  testing. 

(200)  When  a melt  is  rolled  into  several  varie- 
ties of  material  a test  piece  shall  be  taken  from  each  va- 
riety. 

(201)  The  ultimate  strength  of  the  several 
grades  of  steel,  as  determined  from  the  test  pieces, 
shall  be  within  the  following  limits : 

Hard  steel,  70,000  to  78.000  lbs.  per  square  inch. 

Medium  steel  62,000  to  70,000  lbs  per  square  inch. 

Soft  steel,  54,000  to  62,000  lbs.  per  square  inch. 

Rivet  steel,  50,000  to  58,000  lbs.  per  square  inch. 


Elastic  Limit 


Elongation 


Reduction 

of  area 


Fracture 

Bending 


Hard  Steel 


Medium  Steel 


Soft  and  Rivet 
Steel 


Drifting 


—35— 

(20 2)  The  elastic  limit  shall  not  be  less  than  55 
per  cent,  of  the  ultimate  strength. 

(203)  The  elongation  in  8 inches  shall  not  be  less 
than — - 

18  per  cent,  for  hard  steel. 

22  per  cent,  for  medium  steeh 
24  per  cent,  for  soft  steel. 

26  per  cent,  for  rivet  steel. 

(204)  The  reduction  of  area  at  the  point  of  frac- 
ture shall  not  be  less  than — 

35  per  cent,  for  hard  steel. 

40  per  cent,  for  medium  steel. 

45  per  cent,  for  soft  steel. 

48  per  cent,  for  rivet  steel. 

(205)  The  entire  fracture  must  be  silky. 

(206)  A piece  of  each  test  piece  shall  be  bent 
cold  180  degrees. 

(207)  No  specimen  from  hard  steel  shall 
show  any  signs  of  cracks  until  the  diameter  of  the 
circle  around  which  the  bar  is  bent  becomes  less 
than  3 times  the  thickness  of  the  specimen. 

(208)  No  specimen  from  medium  steel  shall 
show  any  signs  of  cracks  until  the  diameter  of  the 
circle  around  which  the  bar  is  bent  becomes  less 
than  the  thickness  of  the  specimen. 

(209)  Each  specimen  from  soft  or  rivet  steel 
shall  bend  180  degrees  and  close  upon  itself  with- 
out sign  of  crack  or  flow  on  the  convex  surface. 

(210)  The  ductility  of  medium  and  soft  steel 
shall  be  such  that  a punched  hole,  the  center  of  which 
is  not  more  than  i\  inches  from  the  sheared  or  rolled 
edge  of  any  piece  may  be  enlarged  by  drifting  to  a diam- 


Duplicate  Tests 


Marking 


Eyebar  Tests 


-36- 

eter  50  per  cent,  greater  than  the  original  hole  without 
cracking  the  specimen  at  any  point. 

(21 1 ) Duplicate  tests  may  be  made  when  the 
sample  fulfills  all  but  one  of  the  requirements.  If  the 
second  test  and  the  average  of  the  two  tests  meet  all 
the  requirements,  the  melt  may  be  accepted. 

(212)  All  material  shall  be  plainly  stamped  with 
a number  identifying  the  melt. 

(213)  The  eyebars  required  for  tests  and  those 
for  the  structure  shall  be  made  at  one  time.  The  test 
bars  to  be  selected  by  the  Inspector,  must  be  fair  aver- 
age specimens  of  those  which  would  be  classed  as  good 
bars  acceptable  for  the  work.  No  bar  which  is  known 
to  be  defective  shall  be  selected  for  testing. 

(214)  These  bars  will  be  required  to  develope  a 
minimum  stretch  of  14  per  cent,  before  breaking  if  of 
soft  steel  and  12  per  cent,  if  of  medium  steel.  The 
elongation  to  be  measured  on  a gauged  length  of  10 
feet  including  the  fracture. 

(215)  If  medium  steel  is  used  the  bars  shall  show 

an  ultimate  strength  of  not  less  than  62,000 — 9.000 
(area  — perimeter)  and  if  soft  steel  not  less  than 
54,000 — 8,000  (area  perimeter).  The  elastic 

limit  in  all  cases  shall  not  be  less  than  55  per  cent,  of 
the  ultimate  strength. 

(216)  In  general  bars  will  be  required  to  break 
in  the  body.  When  a bar  breaks  in  the  head  but  de- 
velopes  14  per  cent,  elongation  before  breaking,  a second 
bar  shall  be  selected  from  the  same  lot.  If  this  bar 
breaks  in  the  body  and  the  average  elongation  of  the 
two  bars  is  not  less  than  16  per  cent.,  the  bars  of  this  lot 
may  be  accepted. 


—37— 


Wrought  Iron 
Grade 


Test  Pieces 

Ultimate 

Strength 


Elastic  Limit 


Elongation 


Bending 


(217)  If  more  than  one-thircl  of  all  the  bars  tested 
break  in  the  head,  this  shall  be  deemed  sufficient  cause 
for  the  rejection  of  the  entire  bill  of  eybars. 

(218)  Tests  of  full  sized  sections  that  meet  the 
requirements  shall  be  paid  for  at  cost  less  the  scrap  value 
of  the  material.  Tests  that  fail/  to  meet  the  require- 
ments will  be  at  the  expense  of  the  Contractor. 

(219)  All  wrought  iron  shall  be  be  the  best 
double  rolled  and  double  refined  iron  It  must  be  tough 
fibrous,  uniform  in  quality,  thoroughly  welded  in  roll- 
ing and  finished  straight  and  smooth.  It  must  be  free 
from  flaws  blisters,  cinder  spots,  cracks  and  imperfect 
edges.  It  must  be  worked  from  the  muck  bar  and  no 
steel  scrap  will  be  allowed  in  its  manufacture. 

(220)  Test  pieces  shall  be  prepared  the  same  as 
for  wrought  steel.  See  paragraphs  197  to  200  inclusive. 

(221)  The  ultirrlate  strength  as  determined  from 
the  test  pieces  shall  no*  be  less  than  50,000  oounds 
per  square  inch. 

(222)  Tension  tests  of  full  sized  bars  must  show 
an  ultimate  strength  of  at  least  52,000 — 7,000  (area 
— perimeter)  in  pounds  per  square  inch. 

(223)  The  elastic  limit  in  no  case  shall  be  less 
than  26,000  pounds  per  square  inch. 

(224)  The  elonga> ton  in  8 inches  shall  be  at  least 
18  per  cent. 

(225)  All  iron  must  bend  cold  180  degrees  to  a 
curve,  the  diameter  of  which  is  not  more  than  twice 
the  thickness  of  the  piece  without  cracking.  When 
nicked  and  bent  the  piece  must  show  no  signs  of  being- 
brittle,  but  shall  bend  and  break  gradually,  showing  a 
uniform  fibrous  fracture. 


Cast  Steel 
Process 

Phosphorus 

Coupon. 

Annealing" 
Blow  holes 

Ultimate 

Strength 

Elastic  limit 

Elongation 

Reduction 
of  area 

Cast  iron 
Grade 


—38— 

(226)  Rivet  iron  must  be  capable  of  being  bent 
double  and  ctosed  upon  itself,  hot  or  cold,  without  sign 
of  fracture  on  the  convex  surface.  When  nicked 
and  broken  the  fracture  must  be  fibrous. 

(227)  All  steel  castings  shall  be  made  by  the  open 
hearth  process  and  shall  be  true  to  pattern  and  of  work- 
manlike finish. 

(228)  The  amount  of  phosphorus  shall  not  ex- 
ceed .08  per  cent. 

(229)  All  castings  shall  be  made  with  a coupon 
for  testing  which  shalli  not  be  cut  off  until  after  the 
castings  have  been  annealed. 

(230)  All  castings  shall  be  thoroughly  annealed. 

(231)  When  the  bearing  surface  of  any  casting 
is  finished,  there  shad  be  no  b’ow  hole  visible  exceeding 
one  inch  in  length  or  exceeding  one-half  square  inch  in 
area.  The  length  of  blow  holes  cut  by  any  straight  line 
shall  never  exceed  one  inch  in  any  one  foot. 

(232)  The  ultimate  strength  as  determined  from 
a J of  an  inch  round  turned  from  the  coupon  shall  be 
from  65000  to  70000  pounds  per  square  inch. 

(233)  The  e’astic  limit  shall  not  be  less  than 
40000  pounds  per  square  inch. 

(234)  The  elongation  shall  not  be  less  than  15 
per  cent,  in  2 inches. 

(235)  The  reduction  of  area  at  the  point  of  frac- 
ture shall  not  be  less  than  20  per  cent. 

(236)  All  iron  castingss  shall  be  made  of  tough, 
gray  iron  and  shall  be  smooth,  sound,  true  to  pattern, 
of  workmanlike  finish  and  must  be  free  from  b’ow 
holes. 


Coupon 


-39- 


Tests 


Phosphor  bronze 
Composition. 


Coupon 

Tests 


Babbitt  Metal 


Timber 


Paint 

Oil 


Red  Lead 


(237)  One  casting  from  each  melt  shall  be  made 
with  a coupon  about  one  inch  square  and  15  inches 
long,  for  testing. 

(238)  Tests  shall  be  made  on  the  coupons  by  ap- 
plying a load  midway  between  supports  12  inches  apart. 
The  test  bars  shall  show  a deflection  of  at  least  .15 
inches  and  develope  a fiber  stress  of  at  least  43000 
pounds  per  square  inch. 

(239)  Castings  of  phosphor  bronze  shall  contain 
88  per  cent,  copper  and  12  per  cent,  phosphorized  tin. 
The  phosphorized  tin  shall  contain  5 per  cent,  phos- 
phorus. 

(240)  Each  casting  shall  be  made  with  a coupon 
from  which  a one  inch  cube  can  be  cut  for  testing. 

(241)  A compression  test  on  this  cube  shall  show 
an  elastic  limit  of  not  less  than  20000  pounds.  The  per- 
manent set  on  the  test  cube  under  a load  of  100000 
pounds  shall  not  exceed  one-sixteenth  of  an  inch. 

(242)  AM  babbitt  metal  shall  be  composed  of  50 
parts  tin,  1 part  copper  and  5 parts  antimony. 

(243)  All  timber  shad  generally  be  white,  oak  or  long 
leaf  yellow  pine.  It  shall  be  first-class  in  all  respects,  sawed 
true  and  of  full  size  and  must  be  free  from  sap  wood  and 
large  or  loose  knots. 

(244)  All  oil  shall  be  bored;  linseed  oil  and  shall 
be  of  a pa'e  yekow  color,  brilliant,  limpid,  drying  well, 
with  a rich  luster,  and  having  a pleasant  nutty  taste. 
Oil  of  a greenish  or  dark  color,  cloudy  or  with  an  uncer- 
tain taste  will  not  be  accepted. 

(245)  All  red  lead  paint  shall  be  high  grade. 
When  properly  mixed  for  use  and  applied  to  a smooth, 
vertical  surface,  it  should  neither  run,  separate  nor  sag. 


—40— 


1st  Field  coat 


2nd  Field  coat 


INSPECTION 

Inspectors- 


Notice  of  rolli 


Surface 

Inspection 


Subsequent 
discovery 
of  defects 


Mirks 


(246)  The  first  field  coat  of  paint  shall  be  the 
“A”  brand  of  “Red  Lead  Metal  Preservative,”  made 
bv  the  Lowe  Brothers  Co.,  of  Dayton,  Ohio. 

(247)  The  second  field  coat  of  paint  shall  be  one 
of  the  following:  First,  Graphite  paint  made  by  the 
Joseph  Dixon  Crucible  Co.,  of  Jersey  City,  N.  J. 
Second,  “Black  Metal  Coating  No.  1407,”  made  by  the 
Lowe  Brothers  Co.,  of  Dayton,  Olr’o. 

(248)  The  Railway  Company  will  empMy  an  Inspector 
who  will  examine  and  test  all  material  before  any  work  is 
done  upon  it.  He  shall  have  free  access  to  the  mills  and 
shops  at  all  times  during  the  construction  of  the  work  and 
shall  have  power  to  reject  material  when  the  material  or 
workmanship  does  not  comply  with  the  requirements  of 
these  specifications. 

(249)  No  material  shall  be  rolled  until  arrangements 
have  been  made  for  the  proper  testing  and  inspection  of  the 
same. 

(250)  Each  and  every  piece  of  material  shall  be  sub- 
mitted to  examination  on  all  sides  and  for  that  purpose 
turned  over  when  required.  All  plates  shall  be  suspended 
for  examination  and  each  piece  shall  be  weighed  separately 
when  required  by  the  Inspector. 

(251)  Acceptance  of  any  material  by  the  Inspector 
shall  not  prevent  its  subsequent  rejection  if  found  defective 
after  delivery,  and- such  material  shall  be  replaced  by  and 
at  the  expense  of  the  Contractor. 

(252)  Material,  when  examined  at  the  rolling  mills 
by  the  Inspector,  shall  when  found  acceptable,  be  stamped 
with  his  private  mark.  No  work  shall  be  done  upon  any 
material  that  does  not  bear  this  mark.  Small  bars,  rods, 


facilities 

full  ske  tests 

MAINTE- 

NANCE 

First  Painting: 


Second 

Inspection 


—4i~ 

etc.,  may  be  put  up  in  bundles  with  the  Inspector’s  mark 
on  a metal  tag  wired  to  the  same. 

(253)  All  facilities,  labor,  tools  and  instruments  ne- 
cessary for  the  inspection  and  testing  of  all  material  in  ac- 
cordance with  the  letter  and  intent  of  these  specifications 
shall  be  furnished  free  of  expense  to  the  Railway  Company. 

(254)  Upon  request,  the  contractor  shall  be  advised 
as  to  the  number  of  pieces  required  for  full  size  tests. 

(255)  The  life  of  a steel  bridge  depends  quite  largely 
upon  the  care  it  receives  and  in  view  of  this  fact  the  Author 
recommends. 

(256)  That  the  bridge  be  repainced  whenever  the 
final  coat  becomes  deteriorated  and  exposes  the  first 
field  coat  of  paint.  A11  efiforu  should  be  made  to  at  all 
times  keep  the  first  field  coat  protected.  Before  repaint- 
ing all  surfaces  should  be  thoroughly  cleaned,  using 
wire  brushes  and  steel  scrapers  where  necessarv.  The 
paint  used  should  be  the  same  as  that  used  for  the  sec- 
ond field  coat.  A marked  difference  in  the  colors  of  the 
first  and  second  field  coats  has  been  selected  in  order  to 
more  clearly  show  when  the  bridge  needs  painting. 

(257)  That  the  bridge  should  be  inspected  at 
frequent  intervals  by  some  competent  person  and  any 
necessary  repairs  be  made.  Especially  should  the  rivets 
in  the  floor  system  be  tested  and  if  any  are  found  loose 
cut  and  replace. 


# 

APPENDIX. 

I 


-43- 

Table  giving  maximum  moments  (M)  and  end  reac- 
tions (R)  for  a train  of  80000  pounds  street  cars  each  40 
feet  long  cen  er  to  center  of  couplings  and  upon  a wheel 
base  of  5 plus  20  plus  5 equals  30  feet  and  the  values  of  w 
based  upon  M and  also  upon  R where  the  equivalent  load  is 
“w  pounds  per  lineal  foot  uniformly  distributed  plus  10  w 
pounds  concentrated,  so  placed  as  to  give  the  maximum  effect 
in  every  case.,, 


Span 
in  feet 


M in  foot  pounds. 


R in  pounds 


W based  on 


10 

56250 

30000 

1 5°°  1 

2000  | 

12 

75210 

31670 

1567 

T979 

l6 

113910 

35000 

1582 

1945  1 

20 

153120 

40000 

i53i 

2000  ! 

24 

211670 

4667O 

1604 

2121  i 

28 

277820 

5I43° 

1654  1 

1 2143  ! 

32 

355600 

55000 

1701 

2115 1 

36 

433800 

57780 

1721 

2063 1 

40 

5I255° 

60000 

1708 

2000  ! 

44 

591300 

63640 

1680 

! 1989  : 

48 

67O4OO 

67920 

1643 

1998  i 

52 

749600 

7r93° 

1602 

1998  : 

56 

85OOOO 

75720 

r598 

T993  : 

60 

950000 

80000 

1583 

2000  , 

64 

1070000 

83750 

x592 

1994  ! 

68 

I 190000 

89410 

i59i 

2032  I 

72 

I 320000 

93330 

1594 

2029  ! 

76 

1460000 

96850 

1601 

2018  * 

80 

l600000 

100000 

1600 

! 2000  j 

84 

1780000 

103800 

1630 

! T997  ! 

88 

1960000 

107950 

1650 

1999  : 

92 

2150000 

1 1 1950 

1661 

! J999  1 

96 

2350000 

1 1 7700 

1688 

| 2030  I 

1 bo 

2550000 

120000 

1700 

2000  j 

!05 

2800000 

125720 

I7°7 

2010  j 

no 

3050000 

1 30900 

1706 

1 2014  1 

IT5 

3400000 

1 3 59oo 

1752 

I 2013  ! 

120 

3900000 

140000 

1857 

2000  : 

125 

3925000 

144800 

1732 

1 1997  ’ 

150 

565OOOO 

170700 

1 T773 

2008  1 

200 

9950000 

| 220000 

| 1809 

! 2000  i 

While  the  above  table  is  not  necessarily  exact,  it  is  close 
enough  to  illustrate  the  value  of  the  loadings  selected  in 
these  specifications. 


— 44- 

Tab -e  giving  maximum  moments  (M)  and  end  reac- 
tions (R)  for  a train  of  pressed  steel  cars  weighing  as  fol 


lows : 

Rated  capacity 100000  pounds 

Excess  load  io  per  cent ioooo  pounds 

Weight  of  car 40000  pounds 


Total  load  for  each  car 150000  pounds 


each  car  having  a length  of  32  J feet  center  to  center  of  coup- 
lings and  a wheel  base  of  5 plus  15  plus  5 equals  25  feet,  and 
the  values  of  w based  upon  M and  also  upon  R where  the 
equivalent  load  is  “w  pounds  per  lineal  foot  uniformly  dis- 
tributed plus  10  w pounds  concentrated  so  placed  as  to  give 
the  maximum  effect  in  every  case.” 


W based  on 


in  feet 

M in  foot  pounds. 

R in  pounds 

M 

1 R 

IO 

105460 

S62S°  1 

2812 

3750  i 

12 

I4IOOO 

59375  ! 

2938 

3711  i 

1 6 

2543OO1 

71480 

3532  | 

3971  ! 

20 

328120 

84375 

I 3281 

4218 

24 

453 !oo 

95312 

3432 

4332  ! 

28 

600000 

103130 

[ 3572 

4297 

32 

747700 

IO898O 

i 3595 

4191  | 

36 

895800 

117190 

3555 

4185'  ! 

40 

1044200 

I26560 

1 348i 

4219  [ 

44  1 

1 162500 

I355IO 

3303 

4235  ’ 

48  i 

1387500 

I453IO 

1 340i 

4274  i 

52  | 

1612500 

155770 

3446 

4327  1 

56 

1846900 

166070 

1 3472 

437° 

60 

2132500 

175000 

3554 

4375  ! 

64 

2428000 

182810 

1 36x3 

4353  | 

68 

2690600 

191360 

i 3597 

4349  ' 

72 

3028100 

200520 

1 3657 

43fc  j 

76 

3375ooo 

209700 

37oi 

4369 

80 

3750000 

219140 

3759 

4383  i 

84 

4162500 

229020 

3811 

4405  i 

88 

4575ooo 

239060 

3851 

4427  1 

92 

5006200 

24823O 

3887 

4433  ' 

q6 

5456200 

25664O 

3920 

4425  | 

100 

5906200 

265310 

3938 

4422 

105 

6468800 

27679O 

3943 

4429  | 

1 10 

7078100 

288070 

3960 

4432 

IT5 

7687500 

300000 

3961 

4445  1 

120 

8343800 

312500 

3972 

4465  1 

125 

9421900 

324000 

4159 

4469 

150 

13078000 

381250 

4104  ! 

44^6  j 

200 

23109000 

495940 

4202 

4508  | 

While  the  above  table  is  not  necessarily  exact,  it  is  close 
enough  to  illus  rate  the  value  of  the  loadings  selected  in  these 
specifications. 


45 

Table  giving  maximum  moments  (M)  and  end  reac- 
tions (R)  for  various  spans  for  E 40  loading  of  Theodore 
Cooper’s  Specifications  and  the  values  of  “w”  based  on  M 
and  also  on  R where  the  equivalent  load  is  “w  pounds  per 
lineal  foot  uniformly  distributed  plus  10  w pounds  concen- 
trated , so  placed  as  to  give  the  maximum  effect  in  every 


Span 
in  feet 

M in  foot  pounds. 

S in  pounds 

w 

based  on 

M 

1 s 

IO 

I I25OO 

60000 

3000 

! 4000  ; 

12 

160000 

70000 

3333 

4375  : 

l6 

280000 

85OOO 

3889 

1 4722 

20 

412500 

I OOOOO 

4125 

1 5000  1 

24 

570400 

I 10800 

4321 

5036  ! 

28 

73IOOO 

120800 

435i 

1 5033 

32 

910800 

131500 

4379 

5°58  : 

36 

IO97OOO 

! 141100 

4354 

1 5°40  ; 

40 

131 IOOO 

1 1 50800 

4370 

1 5027  ; 

44 

1543000 

1 161100 

4384 

1 5034  : 

48 

I 776000 

| 169600 

4353 

4989 

52 

2030000 

178500 

4338 

4959 

56 

2304OOO 

186000 

4331 

4895  ! 

GO 

25990OO 

195200 

4332 

4880  ! 

64 

291 IOOO 

205200 

4332 

| 4886  | 

68 

3247000 

215600 

434i 

4900  i 

72 

3584000 

226700 

4339 

4929  ! 

26 

3942000 

238100 

4323 

1 496 1 

80 

4321000 

248400 

4321 

4968  ! 

84  | 

4713000 

259000 

43i6 

498 1 I 

88 

5128000  1 

269400 

4317 

4989  1 

92 

5552000  ! 

279600 

43ii 

4993  1 

96 

5988000 

289600 

4302 

4994  1 

100 

6440000 

300000 

4293 

1 5000  | 

105 

7075000 

312200 

43!2 

1 4994  ! 

no 

7774000 

324000 

4349 

4985  ; 

115 

8490000 

335800 

4375 

! 4975  ! 

120 

9228000 

347400 

4394 

4963 

125  1 

9993000 

358800 

4411 

1 4950  ; 

150  1 

141 12000 

414670 

4428 

[ 4879  ; 

200  | 

23712000  | 

522000 

43!2 

1 4745  ; 

Load  equivalent  to  E 40  equals,  say  5000  pounds  uniform 
plus  50000  pounds  concentrated,  based  on  R and  4500  pounds 
uniform  plus  45000  pounds  concentrated,  based  on  M. 


-46- 


Table  giving'  a comparison  between  the  loads  used  in 
these  specifications  and  the  tpyical  loads  shown  in  Theodore 
Cooper’s  Specifications : 

equals  E 16.  (2-  56.8  ton  engines  followed  bv  1600 
pounds  per  lineal  foot.) 

equals  E 24  (2-  85.2  ton  engines  followed  by  2400 
pounds  per  lineal  foot.) 

(2-106.5  t°n  engines  followed  by  300a 
pounds  per  lineal  foot.) 

equals  E 32  (2-1 13. 5 ton  engines  followed  by  3200 
pounds  per  lineal  foot.) 

, 1 

(2-124.2  ton  engines  followed  by  350I} 
pounds  per  lineal  foot.) 

equals  E 40  (2-142.0  ton  engines  followed  by  4000 
pounds  per  Lineal  foot.) 

equals  E 48  (2-170.4  ton  engines  followed  by  4800 
pounds  per  Lineal  foot.) 

(2-177.5  toil; engines  followed  by  5000 
pounds  per  lineal  foot.) 


L 20 

equals  E 16. 

L30 

equals  E 24 

r 37-5 

equals  E 30 

L40 

equals  E 32 

L 43-75 

equals  E 35 

L 50 

equals  E 40 

L60 

equals  E 48 

L62.S 

equals  E 50 

—47— 


« *ye  or  <P =•  o O.J  6.2  03  04  O.S  06  07  0-8  09  JO 


—4«— 


/oo 


/so 


eoo 


aso 


t . 


